The US Pacific Fleet said Wednesday that aircraft carrier USS Theodore Roosevelt headed out to sea from Naval Base Guam after nearly two months of being under quarantine there.

The carrier set sail to test the critical systems required to sustain it during its upcoming operations. This simulation process, or "fast cruise," is a key step for the carrier to recommence its scheduled deployment, the fleet explained in a statement on its website.

During the process, the ship remained in waters off the coast of Guam so its pilots and air crews could be re-certified for flight operations.

"Our sailors have tested all of the ship's systems individually, but this is our opportunity to integrate all of that together and show that (USS) Theodore Roosevelt is ready and able to go back to sea," said Captain Carlos Sardiello, commanding officer of USS Theodore Roosevelt, according to the fleet's statement.

Lieutenant Commander DeCrisha Nolan, USS Theodore Roosevelt's training officer, was quoted as saying that the ship must pass a rigorous certification process before deployment, validating the crew's ability to safely navigate, launch and recover aircraft and respond to onboard emergencies.

In addition to testing the ship's systems, its crew have implemented new measures to protect themselves from possible exposure to COVID-19, the fleet said, adding the crew had learned to conduct their normal duties while wearing masks and maintaining social distance over the past seven weeks.

Theodore Roosevelt is America's fourth Nimitz-class aircraft carrier, with a crew of nearly 5,000 sailors who support and conduct air operations at sea.

It departed San Diego in California for a scheduled Indo-Pacific deployment on Jan. 17 but had to dock in Guam on March 27 due to an outbreak of the novel coronavirus on board the ship.

After testing was carried out, it was found that a quarter of the sailors on board the ship were infected with COVID-19, with a 41-year-old chief petty officer later dying from it.

The carrier and its crew recently became embroiled in controversy after Captain Brett Crozier, the ship's then commanding officer, wrote a letter to the Navy, asking Washington to do more to stem the spread of the coronavirus among the crew. The letter was later published by the San Francisco Chronicle, bringing it to the attention of national media.

Crozier was fired by then-acting Navy Secretary Thomas Modly, who resigned following comments he made to the ship's crew in Guam, where he blasted Crozier as being "naive" and "too stupid."